F. Henry Firsching
School of Sciences
Southern Illinois University
Plastics are synthetic materials that have been mostly developed within
the past 50 years. This is such a short time that no organisms or micro-organisms
have evolved that might feed on these materials. When placed in landfills,
plastics persist for indefinite periods of time.
Plastics represent a significant part of overall trash; about seven percent
by weight of all trash is classified as plastic. But by volume plastics
represent about 20 to 30 percent, because so much of the plastics are empty
bottles or containers. The total weight of plastic trash is about 30 billion
pounds annually, or 15 million tons.
Currently, about one billion pounds are recycled, about three percent of
the total. That is not enough reuse. We must do better than that.
There are about five basically different types of plastics, and normally
they cannot all be used together. For example: polyethylene, used in bread
wrappings and dry cleaning bags, is a soft, pliable material. Polyvinyl
chloride, used for floor tiles, is hard and somewhat brittle, while nylon
is a totally different item. If reuse involves putting all these together,
only limited applications are possible.
The Europeans are about ten years ahead of Americans in handling this problem.
They have developed this technology for sorting out various types of plastics.
Once separated, a specific plastic will have specific uses.
One successful application for reused plastic is in construction materials
for homes and other buildings. Mixed plastics, items that cannot be sorted
out satisfactorily, are fused together to make boards of plastic. These
boards are relatively inexpensive when compared to lumber, and, no organisms
or micro-organisms attack them. Termites cannot feed on them, nor can anything
Plastic boards appear to be a major use of mixed plastics. And these boards
can be produced in very large quantities.
More imaginative uses for plastics are possible. The makers of Spic and
Span cleaner are planning to put all cleaners in bottles made of recycled
plastics. The Chrysler Corporation is going to make fenders on 1992 vans
from recycled soft drink bottles.
Other possible uses include: carpets, fibers, fiber-fill stuffing, carstops
in parking lots, piping, planters for flowers, highway signs, etc. Reusing
plastics will have a two-fold impact. Massive trash problems will be reduced
and energy requirements needed to make new plastics will also be reduced.
And, both of these problems, trash and energy, need all the help they can